The present disclosure relates to an image forming apparatus including a sheet feeding unit which feeds a sheet.
In an image forming apparatus, such as a copying machine and a printer, a sheet is fed from a sheet feeding cassette to an image forming part by a sheet feeding unit. The sheet feeding unit includes a feed member and a separation member. The feed member feeds the sheet stored in the sheet feeding cassette. The separation member comes into pressure contact with the feed member to convey an uppermost sheet only.
The separation member is configured to apply friction resistance to the sheets other than the uppermost sheet and to prevent the stacked sheets to be conveyed (prevent the multiple feeding). If stick slip occurs between the separation member and the sheet when the sheet passes through a space between the feed member and the separation member, the separation member and the sheet are vibrated. Then, the vibration is transmitted to the sheet feeding cassette and the others to generate abnormal sound.
In order to prevent the generation of abnormal sound, in some cases, a weight member as a member to restrain the transmission of vibration is mounted to the sheet feeding cassette to which the separation member is attached.
However, although the weight member makes it possible to prevent the vibration of the sheet feeding cassette, it is not sufficient to restrain the transmission of vibration to the feed member which comes into contact with the separation member. If the vibration is transmitted to the feed member, the vibration may be transmitted to a holder which supports the feed member, a feed frame which supports the holder, and a side plate which supports the feed frame. Then, theses member are also vibrated to generate abnormal sound. In order to prevent the generation of abnormal sound, the holder, the feed frame and the side plate may be formed so as to have high rigidity. However, this causes increase in cost.
In addition, in order to restrain the vibration of a relatively large size member, such as the sheet feeding cassette, it is required to increase a weight of the weight member and to increase the number of the weight member. This causes increase in cost.